Ergothioneine: The most powerful antioxidant you've never heard of

Mushrooms are a natural source of L-ergothioneine

Written by Katie Koschalk, a health and wellness writer, certified holistic nutritionist, and certified personal trainer based in California.

When it comes to the pursuit of longevity, antioxidants often take center stage—and one lesser-known yet increasingly fascinating player is ergothioneine (aka ERGO). Found primarily in mushrooms, this naturally occurring compound is gaining attention for its potential role in supporting healthy aging, cognitive function, and mitochondrial energy. Read on to learn more.

What Is Ergothioneine?

Ergothioneine (pronounced ur-go-thigh-uh-neen) is an amino acid derivative (specifically derived from histidine, which is an essential amino acid).

Unlike other antioxidants, your body has a dedicated and highly specific transporter called ERGO transporter (ETT). This transporter pulls ergothioneine from food and distributes it all over the body.

This specificity of this transport has intrigued scientists, who believe ergothioneine may serve a critical (though not yet fully understood) function in human health.

Where Does Ergothioneine Come From?

Humans can’t produce ergothioneine. Rather, it’s made by certain fungi and soil-dwelling bacteria. Plants can absorb it from the soil, and we ingest it when we eat certain foods.

Mushrooms are by far the richest source of ergothioneine. King oyster, maitake, shiitake, and porcini mushrooms are particularly potent. Other sources include chicken liver, tempeh, black beans, wheat germ, oats, asparagus, and garlic, though these contain significantly less.

According to Robert Beelman, professor emeritus of food science at Penn State, to significantly boost ergothioneine intake through diet alone, a person would need to eat about three to four ounces of button mushrooms or an ounce of shiitake mushrooms daily. However, consistently consuming that many mushrooms daily isn’t practical for most people, which is why there’s growing interest in ergothioneine supplements.

One such supplement is MitoPrime® by NNB Nutrition—a highly purified form of L-ergothioneine that doesn’t rely on mushrooms as a source. Instead, it’s produced through a patented natural fermentation process that yields a 99% pure L-isomer. This method delivers optimal potency and bioavailability while offering a more sustainable alternative to mushroom-derived sources.

How Does Ergothioneine Work in the Body?

Once absorbed, ergothioneine appears to concentrate in cells and tissues exposed to high levels of oxidative stress. Unlike more reactive antioxidants, ergothioneine is remarkably stable and doesn’t get used up quickly. That means it can linger in cells and offer long-term protection against damage caused by free radicals and inflammation—both of which are strongly associated with aging and chronic disease.

It also has a unique ability to protect mitochondria, the energy-producing centers of cells, from oxidative stress. This has implications for everything from maintaining cognitive function to supporting cardiovascular and metabolic health.

Potential Health Benefits

While research is still emerging, early studies suggest ergothioneine may play a role in reducing the risk of age-related diseases associated with cognitive decline and cardiovascular health. It has demonstrated anti-inflammatory effects, protective impacts on brain cells, and the ability to reduce oxidative stress in animal and cell studies.

Some researchers have gone so far as to propose that ergothioneine be classified as a “longevity vitamin,” saying that it may be crucial for long-term health and disease prevention.

The Bottom Line on Ergothioneine

Ergothioneine may not be as well-known as vitamin C or resveratrol, but its targeted antioxidant properties and presence in long-lived people suggest it could be an important piece of the longevity puzzle.

Whether through mushroom-rich meals or supplements like MitoPrime®, this under-the-radar compound is worth keeping an eye on as science continues to unlock its potential.